GEOLOGY AND PALEONTOLOGY OF
THE BUREAU OF LAND MANAGEMENT
DOUGLAS POINT SPECIAL RECREATION
MANAGEMENT AREA
CHARLES COUNTY, MARYLAND
December 2008
Lower Potomac Field Station
Eastern States
B
LM
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GEOLOGY AND PALEONTOLOGY OF THE BUREAU OF LAND MANAGEMENT
DOUGLAS POINT SPECIAL RECREATION MANAGEMENT AREA,
CHARLES COUNTY, MARYLAND
INTRODUCTION
The Bureau of Land Management’s (BLM’s) Douglas Point Special Recreation Management
Area (SRMA) is located on the east side of the Potomac River in southwestern Charles County,
MD. Douglas Point SRMA is part of the Nanjemoy Natural Resource Management Area
(NRMA) which is jointly managed by the BLM and the Maryland Department of Natural
Resources (MDNR). The area is accessible via the Potomac Heritage Trail that is about one mile
south of the junction of Liverpool Point Road and Maryland State Route 224. The SRMA is
open to hiking, wildlife observation, fishing, and beachcombing – which includes fossil
collecting on the State of Maryland-owned beaches. The SRMA and vicinity was host to human
occupation over thousands of years, and BLM has interpreted the historic Chiles Home Site in an
area of colonial settlement that began in the 1650’s. Today, the beach along this part of the
Potomac River is a popular fossil shark teeth collecting area amongst amateur collectors. This
report is a description of the geology and paleontology of the Douglas Point SRMA along the
banks of the Potomac River with some recommendations for management of the paleontological
resources.
METHODOLOGY
A literature search using the Internet was conducted and field visits were made to the site to
verify the geology and paleontology of the area. Lists of taxa found in the literature and on the
Internet are compiled in the appendices. Literature and Internet references used for this report
are found in the reference section.
ACKNOWLEDGEMENTS
Special thanks to Mike Folmer and Chuck Ball, amateur paleontologists from Maryland, for their
help and assistance with the field reconnaissance of the Douglas Point SRMA. Special
recognition and appreciation is given for the preparation of display cases of representative fossils
found in the Douglas Point and Liverpool Point areas for BLM’s environmental education
program. Special thanks also goes to Dr. Robert E. Weems, paleontologist with the U.S.
Geological Survey for his help in identifying fossil specimens collected from the Douglas Point
SRMA. This report was prepared by Lucia Kuizon, National Paleontologist, Bureau of Land
Management, Washington, DC. This manuscript was updated on February 24, 2009.
GEOLOGIC SETTING
Charles County, MD, is located within the Atlantic Coastal Plain Physiographic Province. Study
of the geology of the Atlantic Coastal Plain and its Tertiary-age geologic formations began in the
mid-1700’s (1901, Clark and Martin, p. 24.) Many geologic and paleontologic studies based on
continuing research were written throughout the 19th
and 20th
Centuries, especially the
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paleontological work of T.A. Conrad with the Philadelphia National Academy of Sciences and
the geologic and paleontologic work of William Bullock Clark with the U.S. Geological Survey
and later with the Maryland Geological Survey. Sir Charles Lyell, one of the founding fathers of
geology, also wrote about the geology of Maryland and the Tertiary deposits of the Mid-Atlantic
Coast in the 1840’s (Lyell’s Travels in North America: 1841-1842, vol. 1, 1845). More recently,
the geology of the Potomac River and vicinity has been extensively studied by geologists and
paleontologists of the U.S. Geological Survey (USGS), the Maryland Geological Survey, the
Virginia Division of Mineral Resources, and the National Museum of Natural History.
The Atlantic Coastal Plain Physiographic Province is characterized by unconsolidated
sedimentary rocks of sand, silt, and clay eroded from mountains that once existed to the west in
the Piedmont Plateau Physiographic Province, and then were deposited along the continental
shelf (see Figure 1). These sedimentary units were laid down during a period of transgressions
and regressions of the Atlantic Ocean over millions of years (Cretaceous to Quaternary) in an
area known as the Salisbury Embayment, a tectonic basin that was part of a series of basins and
arches (down warps and uplifts) along the Atlantic Coast of the United States. (Ward and
Powars, 2004, p. 265-272). The Atlantic Coastal Plain is further subdivided into sub-provinces,
Douglas Point SMRA being in the Western Shore Uplands Region west of the Chesapeake Bay.
The Western Shore Uplands is characterized by more relief, i.e., it is slightly hillier with higher
elevations than the area east of the Chesapeake Bay (Schimdt, 1993, pp. 3-6.)
Figure 1. Physiographic Provinces in Maryland. The Atlantic Coastal Plain Physiographic Province is subdivided
into the Western Shore Uplands Region and the Western Shore Lowlands Region. Douglas Point is in the Western Shore Uplands Region (Conkwright, 2001).
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Figure 2. Geologic Time Scale and Stratigraphy at Douglas Point SMRA, MD (after ICS, 2008).
GEOLOGY
Geologic formations of the Atlantic Coastal Plain exposed at Douglas Point SMRA were
deposited during the Tertiary and Quaternary Geologic Time Periods (see Figure 2 and Appendix
2). The geologic units exposed on the surface at Douglas Point SMRA are Quaternary
Pleistocene surficial deposits made up predominantly of Potomac River terrace and other alluvial
silt, sand and gravel deposits (see Figure 3). The soils that were formed from these deposits host
Eastern Woodlands vegetation. The geology of the Atlantic Coastal Plain was also impacted by
the last glacial and interglacial periods (glacial cycle) that began about 135,000 years ago
(Krantz et al, 2007, in press). Although there was no continental ice that actually extended as far
south as Maryland, the rise and fall of sea level during the glacial cycle influenced the deposition
of the Quaternary formations. Isostacy – the rise and fall of the continental crust as a result of
the weight of glacial ice – impacted the topography by creating incised river channels, especially
during isostatic, or post-glacial, rebound when the weight of the ice was removed as it retreated
northward.
The Potomac River incised channel exposes the Late Paleocene Aquia Formation along the
bluffs at the Douglas Point SMRA (see Figure 4). The Aquia Formation was deposited between
55 and 60 million years ago, about 5 million years after the impact of an asteroid or meteor at the
end of the Late Cretaceous that wiped out about 75% of life on Earth including the dinosaurs.
The sedimentary rocks of the Aquia Formation were formed in a shallow near-shore marine
(neritic) environment over this period of time. They contain a large amount of ―greensands,‖ i.e.,
they contain high concentration of the mineral glauconite – a green phyllosilicate mineral or
silicate hydroxide containing potassium, sodium, iron, aluminum, and magnesium. The amount
of glauconite contained in a sedimentary unit is directly related to the distance from the original
source rock in the Piedmont to the west to the shoreline where the material was deposited as well
as the amount of the mineral biotite in the original source rock.
At the base of the cliff and along the beach at Blue Bay between Liverpool Point and Douglas
Point, the Aquia Formation is composed mainly of indurated (hard and compact) shelly units of
ERA PERIOD EPOCH FORMATION MEMBER AGE/Sub-age
CENOZOIC
Quaternary Pleistocene Undifferentiated
0.0117 To 1.806 Ma
Tertiary
Pliocene Not present
Miocene Not present
Oligocene Not present
Eocene Not present
Paleocene Aquia Formation (Late Paleocene)
Paspotansa
Member
Thanetian = 58.7 ± 0.2 Ma to 55.8
± 0.2 Ma Selandian =
58.7 ± 0.2 Ma to ~61.1 Ma
Piscataway Member
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glauconitic sands and clay (see Photo 1). These shelly units are characteristic of the Piscataway
Member of the Aquia Formation and are the source of the majority of the fossils found at
Douglas Point SRMA. South of Blue Bay at Douglas Point, a pebble/cobble conglomerate unit
crops out along the beach, and marks an erosional contact with the overlying Pleistocene
surficial deposits of the Maryland Point Formation (Davis et al, 2001). The Paspotansa Member
of the Aquia Formation is not exposed on the banks of the Potomac at the Douglas Point SRMA.
Photo 1. Outcrop of Piscataway Member of the Aquia Formation at Douglas Point SMRA at Blue Bay. Ruler in photo = 7.5 inches.
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Figure 3. Surficial Geology, Charles County, MD from USGS Open File Report 01-227 (Davis et al, 2001)
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Figure 4. Idealized geologic cross-section at Douglas Point SMRA, Maryland (after Maryland Department of
Geology, Mines and Water Resources, 1948).
1 Explanation of surficial geologic units at Douglas Point SMRA:
Qmp1 – Maryland Point Formation. Fine to medium, poorly to moderately well sorted, light- to dark-gray sand, in
part, clayey and silty. Constitutes surficial terrace deposits.
Qmp2 –Maryland Point Formation. Fine to coarse, poorly to well-sorted, gray sand, weathers grayish orange.
Contains plant fragments and oyster beds. Unit consists of extensive surficial terrace deposits.
Qcm - Chicamuxen Formation (lower Pleistocene) -- Coarse gravelly sand and clay-silt grades.
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PALEONTOLOGICAL SETTING
Maryland has played an important role in the study and lure of paleontology. In 1858, one of the
first discoveries of North American dinosaurs was found in Prince Georges County. Two teeth
of Astrodon johnstoni, a sauropod dinosaur, were discovered in a marl pit in Early Cretaceous-
aged clays near Muirkirk in Prince George's County (2004, Maryland Geological Survey).
Astrodon johnstoni was officially named Maryland’s state dinosaur in 1998.
Interest in fossil collecting in Charles County and at the Douglas Point SRMA goes as far back
as colonial days as evident from the fossil sharks teeth collected from the Chiles Home Site
during archaeological excavations by William and Mary Center for Archaeological Research in
2005. The first comprehensive paleontological research studies of Maryland were by T.A.
Conrad with the Philadelphia Academy of Natural Sciences in the 1830’s. His work included
identifying and naming new species of invertebrate fossils from Clifton Beach, south of the
Douglas Point SRMA and Purse State Park.
PALEONTOLOGY
Many fossil species have been identified and studied from the Aquia Formation in Virginia and
Maryland by paleontologists and amateur collectors. The type section, or the sequence of rock
strata where the Aquia formation was originally described, is near Aquia Harbor in Stafford
County, Virginia. The formation was originally thought to be of the Eocene Epoch, but
subsequent paleontological research of ancient foraminifera (a single-celled organism belonging
to the Order Foraminiferida in the Phylum Protozoa) from the Aquia Formation showed that it
was older, and deposited (or formed) during the Late Paleocene (see Figure 2 or Appendix 2).
This is a great example of how fossils (called index fossils) are used to date rock formations in
geologic time.
The Linnaean System of the Classification of Life (Systematics)1
Kingdom Phylum Subphylum Class Order Family Genus
Species 1 There can be subunits of each level such as Superclass and Subclass.
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The diversity of fossils found at the Douglas Point SRMA include invertebrates (organisms
without backbones), vertebrates (organisms with backbones), and plants. The types of fossils are
predominantly body fossils, or remains of body parts, which may or may not have undergone the
process of fossilization. Fossilization is the process whereby the remains – a body part or trace –
of an organism, whether plant or animal, were preserved in the Earth's crust. The process usually
involves rapid burial after death and replacement of organic matter with inorganic minerals that
replicate the remains of the organism.
Some of the typical invertebrate fossils found at Douglas Point SMRA include oysters, clams,
giant clams, gastropods, ammonites, and cephalopods. Vertebrate fossils found here include
many species of extinct sharks, bony fishes, rays (related to sharks), turtles, crocodiles,
mammals, and birds. Plant fossils have also been found particularly pinaceous cones. Body
fossils found at the Douglas Point SRMA include whole and partial shells, shell fragments, bones
of fish, reptiles, mammals, and birds, otoliths (or inner ear concretions in fish), scutes and costals
of turtles, and teeth of sharks, rays, and other fish. In addition to body fossils, trace fossils have
also been found including coprolites (or fossilized excrement) of crocodiles and steinkerns (or
internal molds) of the gastropod (snail), Turitella sp. as well as other mollusks.
Lists of the fossils by taxa, or unit of ranking within the Linnaean Taxonomic Classification
System, which have been identified at localities in and around the Douglas Point SRMA, will be
found in the Appendices. Localities include Liverpool Point, north of the SRMA, Clifton Beach
and Wades Bay, South of Douglas Point and the SRMA, and Blue Bay within the SRMA. The
taxa lists only include species found in the Piscataway Member of the Aquia Formation found in
Maryland where possible. The Paspotansa Member of the Aquia Formation contains many of
the same fossils as well as other distinct fossil taxa that do not occur in the Piscataway.
Appendix 3 is a list of taxa identified in the literature. Appendix 4 is a list of taxa identified
from the Internet predominantly web pages of amateur collectors. Appendix 5 is a list of taxa
identified by Mike Folmer and Chuck Bell, amateur paleontologists/ collectors.
Taxonomic Classification (Systematics) of Striatolamia striata var. macrota (?)
Extinct genus of a sand tiger- like shark found at Douglas Point SRMA
Kingdom = Animalia Phylum = Craniata Subphylum = Vertebrata Superclass = Gnathostomata Class = Chondrichthyes Subclass = Elasmobranchii Superorder = Galea Order = Lamniformes Family = Odontaspididae (?) Genus = Striatolamia
Species = striata var. macrota (?) (?) indicates ongoing revision in classification of this taxon.
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MANAGEMENT CONSIDERATIONS
Paleontological Resources
The 2005 Nanjemoy NRMA Land Unit Implementation Plan (LUIP) contains management goals
and recommendations for paleontological resources as well as a site analysis that identifies the
opportunities and constraints within these recommendations. Protection of paleontological
resources for future generations of the public is the overall management goal for fossil resources
in the Douglas Point SRMA. Paleontological resources will be managed for their scientific,
educational, and recreational values. The specific management recommendations are reproduced
below in Table 1.
In situ paleontological resources at the Douglas Point SRMA occur within the Late Paleocene
Aquia Formation exposed along the banks of the Potomac River. Fossils below the mean high
water level belong to the State of Maryland; fossil about the mean high water mark on the
property of the BLM. Fossil remains contained within the banks of the Potomac River at
Douglas Point are scientifically significant because they (1) are found in stratigraphic context
within the Aquia Formation; (2) represent life on Earth 60 million years ago in the Late
Paleocene; and (3) record the history of life after the meteor impact event that occurred 65
million years ago at the end of the Late Cretaceous Period. Collecting of vertebrate
paleontological resources from the cliff face is only allowed for scientific purposes, and requires
a permit from the appropriate agency. However, the incised banks of the Potomac River are
being continuously eroded by water, wind, and tree-fall, and therefore, release fossil remains
onto the beaches along the cliffs. These fossils generally lose their scientific value because they
no longer have stratigraphic context. Therefore, sharks teeth, shells, and other fragmentary fossil
remains found lying along the beach may be collected and taken home. Fossil collecting has
long been a traditional recreational use of the Blue Banks area, Liverpool Point, Purse State Park,
and Clifton Beach. However, some of these eroded fossil remains may retain some scientific
value if they represent (a) a rare taxon, (b) a taxon never before found at this locality, or (c) a
species with a unique morphological feature never observed in other specimens. This issue was
not identified in the Nanjemoy NRMA LUIP. The recommendation to mitigate this issue would
be to educate the local amateur collectors and encourage then to contact a paleontologist at the
National Museum of Natural History, the Calvert Marine Museum, or the U.S. Geological
Survey when they find an unusual fossil specimen. Another issue not identified in the LUIP is
the association of fossil remains found in historic context with the Chiles Homesite and other
historic sites in the Douglas Point SRMA, as well as in association with Paleo-Indian sites.
Recommendations for mitigation would be to educate researchers at Douglas Point SRMA about
the association of fossil remains with historic or Paleo-Indian sites, and to follow MR 30 and 31
for Cultural Resources.
Recreational Opportunities
Take it Outside! Program
The Bureau of Land Management’s (BLM’s) "Take It Outside" program promotes and supports
outdoor activities and experiences of children on the public lands. The program strives to
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improve the health of our nation's children, families, and communities, while at the same time
developing the next generation of public land stewards.
The Douglas Point SRMA would be an ideal location for this program. The SRMA is
particularly ideal because it offers the opportunity for inner city kids in the Washington, DC
metropolitan area to experience what it means to be away from all the concrete, traffic, and
people. Inner city kids would be able to experience and enjoy hiking, beachcombing, and fossil
collecting.
Educational Opportunities
Educating children in outdoor settings is a proven technique for improving student test scores
and motivation; enhancing understanding of natural processes; and promoting attitudes of respect
and responsibility. Curricula, educational talks, and brochures can be developed about (a) the
importance of paleontological resources, (b) introductory geology and other earth processes at
the SRMA, and (c) appropriate fossil collecting do’s and don’ts.
Another program that encourage kids to experience nature and learn about the environment is the
―No Child Inside‖ Program. The emphasis of this program is developing curricula for grades K-
12 focused on environmental education including climate change. A fascinating curriculum
could be developed around the asteroid/meteor impact event that wiped out the dinosaurs and
75% of life on Earth as a result. The Aquia Formation at Douglas Point was deposited about 5
million years after the impact. It also represents what life was like on Earth prior to another
global warming and extinction event that occurred at the Paleocene-Eocene boundary that is
currently being studied by scientists world-wide – the Paleocene-Eocene Thermal Maximum
(PETM).
Safety Issues
1. Cliff Instability. The geologic formations exposed along the incised banks of the
Potomac River are unconsolidated sediments. Therefore, they are extremely unstable
when in vertical or almost vertical angles. In addition to the scientific issue, fossil
collecting from the cliff face must be prohibited unless conducted by qualified scientists
because of the potential for slope failure. Slope failure may also cause the trees along the
cliff edge to become uprooted and fall down.
2. Tides. The Potomac River is an estuary, and therefore, the water levels are influenced by
the orbit of the Moon, i.e., the tides. The beach at Douglas Point SRMA is submerged
during high tides, and therefore, not appropriate for beachcombing and fossil collecting.
Higher water levels that submerge the beach may also occur during periods of high
winds, such as during severe thunderstorms, hurricanes, and tornadoes.
3. Errant Winds. The incised nature of the Potomac River intensifies the winds that travel
down the river channel and may create microbursts and may cause trees at the edge of the
cliff face to blow down. Blow downs may also occur during severe thunderstorms and
tornados.
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Table 1. Paleontological Resources Management Recommendations for the Douglas Point SRMA (2005, Nanjemoy NRMA Land Unit Implementation Plan)
MR No. Recommendation Analysis
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Protect fossils of significance by prohibiting the collection of any fossils still embedded in the exposed cliffs along the shoreline. Exceptions will be made (i.e. professional collectors working for public institutions) for those who have acquired permits issued by the BLM and MDNR. These fossils are important for research and educational purposes and should be placed in museums or other public institutions. Any park visitor finding embedded fossils should (1) leave the fossils in place, and (2) immediately bring it to the attention of the managing agency. However, sharks teeth, shells, and other fragmentary fossils found lying along the beach may be collected and taken home.
In situ deposits of paleontological resources are scientifically significant because they are (a) found in place in stratigraphic context within the Aquia Formation, (b) represent life on Earth in the Late Paleocene, and (c) record the history of the recovery of life after the meteor impact event that took place 65 million years ago in the Late Cretaceous. Therefore, these fossils and other paleontological remains located within the cliff faces (i.e. primary context) are protected by State and Federal law. These remains are not open to collection, disturbance or removal, without prior permission from the BLM and MDNR. Ongoing erosion of the cliff face of the Blue Banks release fossil remains onto the beach. Once these fossils are no longer in situ, they lose their stratigraphic context. Therefore, sharks teeth, shells, and other fragmentary fossil remains found lying along the beach may be collected and taken home. This is compatible with the history of the Blue Banks area as a popular place for beachcombing and collecting fossil remains. Issue not identified in LUIP: Fossil remains no longer in situ may still have some scientific value if they represent a rare taxon or exhibit a morphological feature never before observed in other specimens of the same species. Recommendation: Educate amateur collectors about the potential scientific significance of vertebrate fossil finds and recommend that they contact a paleontologist at the National Museum of Natural History, the Calvert Marine Museum, or the U.S. Geological Survey to determine if they have a significant find.
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Paleontological work in the Douglas Point SRMA must follow the BLM policy for Paleontological Resources.
See Appendix 2, p.2-1 of the Coordinated Management Plan for the Federal Paleontology Program Policy.
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Conduct a paleontological survey to identify any fossil resources that could be impacted in construction of the Blue Banks Beach trail to the Potomac River, and development of the picnic site on the bluff at Blue Banks Beach.
A field reconnaissance of the Douglas Point tract for this geology and paleontology report reveals that the surficial geologic deposits are Pleistocene or younger in age, and are non-fossil bearing. The Late Paleocene Aquia Formation dips 10 to 15 degrees to the east and is therefore only exposed along the banks of the Potomac River. Issue not Identified in LUIP: Sharks teeth and other fossil remains found in context with the historic and archaeological sites within the SRMA are considered cultural resources protected under the National Historic Preservation Act and/or the Archaeological Resources Protection Act. Recommendations: Follow MR 31 for fossils found in context with historic or archaeological sites. Educate researchers to expect this association with sites in the area. Any construction or earth-moving activities at the Douglas Point SRMA should contain the standard stipulation language to protect cultural and paleontological resources as identified in MR 30.
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The BLM, MDNR, and County will ensure that fossils are collected by professionals and placed in permanent, public institutional collections (e.g. Calvert Marine Museum, Smithsonian Institute, or within future Charles County Interpretive Center(s), etc.).
Curation of paleontological resources in a qualified repository is one of the requirements for a federal paleontological resources use permit. See Appendix 2, p.2-1 of the Coordinated Management Plan for the Federal Paleontology Program Policy.
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Figure 5. Poster showing recreational opportunities at the BLM Douglas Point SRMA.
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Appendix 1. Topographic Map with Administrative Boundaries, Douglas Point SRMA.
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Appendix 2 – Geologic Time Scale from Stoffer, 2006.
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APPENDIX 3. Taxa from the Literature
Table 1. Invertebrate Fossils
GENUS - SPECIES LOCATION PHYLUM CLASS REFERENCE Hercoglossa tuomeyi Clifton Beach (CB) Mollusca Cephlapoda 1901, Clark & Martin
Nautilus sp. Clifton Beach Mollusca Cephlapoda 1896, Clark, USGS Bull 141
Cyclichna venusta Clifton Beach Mollusca Gastropoda 1901, Clark & Martin
Caricella pyruloides ? Liverpool Point (LP)
Mollusca Gastropoda 1901, Clark & Martin
Strepsidura subscalarina Liverpool Point Mollusca Gastropoda 1901, Clark & Martin
Tudicla sp. Clifton Beach Mollusca Gastropoda 1901, Clark & Martin
Turritella mortoni CB, LP Mollusca Gastropoda 1901, Clark & Martin; 1939, Bowles
Turritella humerosa CB, LP Mollusca Gastropoda 1901, Clark & Martin
Natica cliftonensis Clifton Beach Mollusca Gastropoda 1896, Clark; 1901, Clark & Martin
Lunatia marylandica Liverpool Point Mollusca Gastropoda 1901, Clark & Martin
Calyptraea aperta CB, LP Mollusca Gastropoda 1901, Clark & Martin
Calyptraea trochiformis Clifton Beach Mollusca Gastropoda 1896, Clark, USGS Bull 141
Cadulus abruptus CB, LP Mollusca Scaphopoda 1901, Clark & Martin
Teredo virginiana Clifton Beach Mollusca Bivalvia 1896, Clark; 1901, Clark & Martin
Phenacomya petrosa Clifton Beach Mollusca Bivalvia 1901, Clark & Martin
Panopea elongata Clifton Beach Mollusca Bivalvia 1901, Clark & Martin
Corbula subengonata Clifton Beach Mollusca Bivalvia 1901, Clark & Martin
Corbula aldrichi CB, LP Mollusca Bivalvia 1901, Clark & Martin
Tellina (Angelus) virginiana Clifton Beach Mollusca Bivalvia 1901, Clark & Martin
Meretrix ovata var. pyga CB, LP, Blue Bay (BB)
Mollusca Bivalvia 1901, Clark & Martin; 1948, Dryden et al
Dosiniopsis lenticularis CB, LP Mollusca Bivalvia 1896, Clark; 1901, Clark & Martin
Lucina uhleri CB, LP Mollusca Bivalvia 1901, Clark & Martin
Crassatellites alaeformis CB, LP, Wades Bay (WB)
Mollusca Bivalvia 1896, Clark; 1901, Clark & Martin
Crassatellites aquiana Liverpool Point Mollusca Bivalvia 1901, Clark & Martin
Crassatellites sp. Clifton Beach Mollusca Bivalvia 1901, Clark & Martin
Pholadomya marylandica Clifton Beach Mollusca Bivalvia 1901, Clark & Martin
Modiolus alabamensis CB, LP, WB Mollusca Bivalvia 1901, Clark & Martin
Lithophaga marylandica Clifton Beach Mollusca Bivalvia 1901, Clark & Martin
Anomia marylandica Clifton Beach Mollusca Bivalvia 1901, Clark & Martin
Ostrea compressirostra LP, WB, CB, BB Mollusca Bivalvia 1896, Clark; 1901, Clark & Martin; 1948, Dryden et al
Gryphaea vesicularis Clifton Beach Mollusca Bivalvia 1901, Clark & Martin
Cucullea gigantea CB, LP, WB Mollusca Bivalvia 1901, Clark & Martin
Leda cultelliformes Clifton Beach Mollusca Bivalvia 1901, Clark & Martin
Leda cliftonensis LP, CB Mollusca Bivalvia 1901, Clark & Martin
Cytherea ovata Clifton Beach Mollusca Bivalvia 1896, Clark, USGS Bull 141
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GENUS - SPECIES LOCATION PHYLUM CLASS REFERENCE Isocardia ? Wades Bay Mollusca Bivalvia 1948, Dryden et al
Venericardia sp. Wades Bay Mollusca Bivalvia 1948, Dryden et al
Naming Conventions
sp. = unidentified or indeterminate taxa
? or cf. = uncertain taxa
var. = multiple varieties
Some common names for the above taxa:
Cucullea gigantea = giant clam
Ostrea compressirostra = oyster
Turritella mortoni = sea snail, gastropod
Hercoglossa tuomeyi = squid-like mollusk with curled shell similar to a nautilus
Cadulus abruptus = tusk shell mollusk: smooth straight conical shell similar to a tusk
Crassatellites alaeformis = clam
Table 2. Vertebrate Fossils
VERTEBRATE FOSSIL
LOCATION SUPER ORDER FAMILY COMMON NAME
REFERENCE
Thecachampsa sp. Liverpool Point
Crocodylo-morpha
Crocodilidae now Tomistominae (false gravials)
Crocodile 1901, Clark & Martin; 2004 & 2006, Brochu
Thecachampsa marylandica var. sericondon?
Clifton Beach Crocodylo-morpha
Crocodilidae Crocodile 1896, Cark; 1901, Clark & Martin
Thecachampsa sericondon ?
Clifton Beach Crocodylo-morpha
Crocodilidae Crocodile 1901, Clark & Martin
Eosuchus minor Blue Bay Crocodylo-morpha
Gavialoidea Longirostrine (long snout) crocodilian
Robert Weems, August 2008, per. Comm.
Thoracosaurus neocesariensis
Blue Bay Crocodylo-morpha
Gavialoidea Longirostrine crocodilian
Robert Weems, August 2008, per. Comm.
Coprolites Clifton Beach Crocodylo-morpha
Unidentified Crocodile fossil excrement
1896, Cark; 1901, Clark & Martin
Euclastes ? sp., Lytoloma? sp. now Lytoloma sp.
Clifton Beach Testudines Chelonidae Sea turtle 1896, Clark; 1901, Clark & Martin; 1936, Collins & Lynn
Trionyx virginiana
Aquia - Virginia
Testudines Trionychidae Fresh water soft shell turtle
Note: reported by amateur collectors near Liverpool Point
VERTEBRATE FOSSIL
LOCATION CLASS ORDER COMMON NAME
REFERENCE
Myliobates copeanus now dixoni
CB, LP Chondrichthyes Rajiformes Eagle Ray 1901, Clark & Martin; Paleobiology database, accessed Sept 2008.
Synechodis clarkia (Paraorthocodus clarkia? Aka
Liverpool Point
Chondrichthyes Synchodonti- formes
Bullhead shark 1901, Clark & Martin (aka Easton, 1901); Ward and Wiest, 1990
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VERTEBRATE FOSSIL
LOCATION CLASS ORDER COMMON NAME
REFERENCE
Paraorthocodus eocaenus?)
Odontaspis cuspidata
Liverpool Point
Chondrichthyes Lamniform Mackerel shark 1901, Clark & Martin
Odontaspis macrota
Liverpool Point
Chondrichthyes Lamniform Mackerel shark 1901, Clark & Martin
Odontaspis elegans
CB, LP Chondrichthyes Lamniform Mackerel shark 1896, Cark; 1901, Clark & Martin
Otodus obliquus Liverpool Point
Chondrichthyes Lamniform Extinct mackerel shark
1901, Clark & Martin; 1990 Ward and Wiest
Sphyrna prisca Liverpool Point
Chondrichthyes Carcharhiniform Hammerhead shark
1901, Clark & Martin
Shark vertebrae CB, BB Chondrichthyes Unknown Unknown 1901, Clark & Martin
Paraorthocodus clarkii (“Synechodos eocaenus?)
Piscataway – Aquia FM, MD
Chondrichthyes Synechodonti-formes
Extinct shark 1990, Ward and Wiest
Squalus orpiensis Piscataway – Aquia FM, MD
Chondrichthyes Squailformes Dogfish shark 1990, Ward and Wiest
Squalus minor Piscataway – Aquia FM, MD
Chondrichthyes Squailformes Dogfish shark 1990, Ward and Wiest
Heterodontus lerichei
Piscataway – Aquia FM, MD
Chondrichthyes Heterodonti-formes
Bullhead shark 1990, Ward and Wiest
Ginglymostema africanum now Delpitoscyllium africanum
Piscataway – Aquia FM, MD
Chondrichthyes Orectolobiformes Extinct nurse shark
1990, Ward and Wiest; 2000, 2002, Bourbon (elasmo.com) after 2005, Carpetta and Nolf
Striatolamia macrota
Piscataway – Aquia FM, MD
Chondrichthyes Lamniformes Sand tiger shark
1990, Ward and Wiest
Carcharias Hopei now--Hypotodus verticalis
Piscataway – Aquia FM, MD
Chondrichthyes Lamniformes Sand tiger shark
1990, Ward and Wiest; 2000, 2002, Bourbon (elasmo.com) after 2005, Carpetta and Nolf
Odontapis winkleri
Piscataway – Aquia FM, MD
Chondrichthyes Lamniformes Sand tiger shark
1990, Ward and Wiest
Palaeohypotodus rutoti
Piscataway – Aquia FM, MD
Chondrichthyes Lamniformes Sand tiger shark
1990, Ward and Wiest
Lamna lerichei Piscataway – Aquia FM, MD
Chondrichthyes Lamniformes Sand tiger shark
1990, Ward and Wiest
Isurolamna inflata
Piscataway – Aquia FM, MD
Chondrichthyes Lamniformes Extinct mackerel shark
1990, Ward and Wiest
18
VERTEBRATE FOSSIL
LOCATION CLASS ORDER COMMON NAME
REFERENCE
Isurus novus Piscataway – Aquia FM, MD
Chondrichthyes Lamniformes Mackerel shark
1990, Ward and Wiest
Palaeocarcharo- don orientalis
Piscataway – Aquia FM, MD
Chondrichthyes Lamniformes Extinct mackerel shark
1990, Ward and Wiest
Paleogaleus vincenti (Daimenes)
Piscataway – Aquia FM, MD
Chondrichthyes Carcharhini-formes
Leopard shark 1990, Ward and Wiest
Scyliorhinus brivesi
Piscataway – Aquia FM, MD
Chondrichthyes Carcharhini-formes
Cat shark 1990, Ward and Wiest
Scyliorhinus gilberti
Piscataway – Aquia FM, MD
Chondrichthyes Carcharhini-formes
Cat shark 1990, Ward and Wiest
Abdounia beaugei
Piscataway – Aquia FM, MD
Chondrichthyes Carcharhiniformes
Requiem shark 1990, Ward and Wiest
Abdounia sp. Piscataway – Aquia FM, MD
Chondrichthyes Carcharhini-formes
Requiem shark 1990, Ward and Wiest
Galeorhinus sp. Piscataway – Aquia FM, MD
Chondrichthyes Carcharhini-formes
Tope shark 1990, Ward and Wiest
Coupateria wouters
Piscataway – Aquia FM, MD
Chondrichthyes Myliobatiformes Eagle ray 1990, Ward and Wiest
?Raja sp. Piscataway – Aquia FM, MD
Chondrichthyes Rajiformes Eagle ray 1990, Ward and Wiest
Myliobatis dixoni (Agassiz)
Piscataway – Aquia FM, MD
Chondrichthyes Rajiformes Eagle ray 1990, Ward and Wiest
Myliobatis sp. Piscataway – Aquia FM, MD
Chondrichthyes Rajiformes Eagle ray 1990, Ward and Wiest
Coprolites Clifton Beach
Unknown Unknown Fossil fish excrement
1896, Cark; 1901, Clark & Martin
Xiphias ? Radiata Clifton Beach
Osteichthyes Perciformes ? Sword-fish 1901, Clark & Martin
Abulidae indet. --- now Paralbula marylandica
Liverpool Point
Osteichthyes Teleostei Albulidae (F) -- now Phyllodontidae
Bony Fish 1936, Myers; 1940, Blake; 1969, Estes
Ischyrhiza (?) radiata Leidy - now Actinopterygian fish indet.
Clifton Beach
Osteichthyes Unknown Ray-finned fish 1896, Clark; 2004, Suarez & Cappetta
19
VERTEBRATE FOSSIL
LOCATION CLASS ORDER COMMON NAME
REFERENCE
Otoliths Clifton Beach
Osteichthyes Unknown Unknown 1896, Clark
Lepisosteus sp. Aquia FM, MD
Osteichthyes Lepisosteiformes Gar fish 1998, Weems
Pycnodus sp. Aquia FM, MD
Osteichthyes Pyncnodonti-formes
Extinct ray-finned fish
1998, Weems
?Phencodus s.p Douglas
Point Mammalia Condylartha Ungulate =
hoofed 2000, Rose
Arctocyonidae indet.
Douglas Point
Mammalia Condylartha Ungulate = hoofed
2000, Rose
Ectoganus cf. gliriformis
Douglas Point
Mammalia Cimolesta Suborder Taeniodonta
2000, Rose
Presbyornis isoni LP, BB Infraclass Aves Anseriformes giant duck-like bird
1994, Olson; 1999, Benson; 2002, Kurochkin et al
Aquia Formation Turtles at Douglas Point SRMA, MD, Charles County Note: The phylogeny of fossil turtles from the Aquia Formation is still being worked out. The following is the story of the status of turtles to date. Testudines Linnaeus,1758 [Holroyd, Parham, Hutchison, 2005:979] Cryptodira Cope, 1868 Trionychidae Gray, 1825 (Softshell turtles) 1. Trionychinae Gray, 1825, Genus indet.
Synonyms: Family Trionychidae Bell 1928, [Hutchison and Weems, 1998:180] Genus Aspideretes Hay 1904 cf. Aspideretes virginianus (Clark, 1895)
Synonyms: Aspideretes virginianus (Clark, 1895), [Weems, 1988:118] Trionyx virginianus Clark [1895:4] Amyda? virginiana (Clark), [Hay, 1908:515] Amyda virginiana (Clark), [Lynn, 1929:1]
2. Catapleura repanda Cope, 1868, [Hirayama, 2006] Synonyms: Dollochelys coatesi, [Weems, 1988:132] 3. Kinosternoid indet. [Hutchison and Weems, 1998], Weems, Sept. 2008, personal communication 4. Catapleura ruhoffi, [Weems, 1988:129] 5. Euclastes roundsi [Parham, 2005:75, 76; Lynch and Parham, 2003:35] Synonym Osteopygis roundsi [Weems, 1988], Weems, Sept. 2008, personal communication 6. Family Toxochelydae Baur, 1895 (pdb) Synonym Family Cheloniidae Gray 1825, Genus indet. [Hutchison and Weems, 1998:184]
Subfamily Osteopyginae Zangerl 1953 (Family in Gaffney and Meylan, 1988)
20
Osteopygis Cope 1868 Propleura Cope, 1869 Lytoloma Cope, 1869 Osteopygis emarginatus Cope, 1868 Synonym Euclastes wielandi (combo. nov.) [Parham, 2005, not accepted] Genus Euclastes Cope 1867 [Clark, 1896, Case,1901] Euclastes? Clark, 1895:4 [1896:59]
Lytoloma? Cope, 1869, [Hay 1908, 364; also Collins and Lynn, 1936, p. 153. "Generically indeterminable"]
Primary source: http://paleodb.org and the literature.
Table 4. List of Other Taxa Found in the Aquia Formation
Planktonic Foraminifera Reference
Ceratobulimina perplexa 1959, Page
Citharina plumoides (Plummer) 1959, Page
Rubulus midwayensis 1959, Page
Bulimina cacumenata 1959, Page
Globanomalina pseudomenardii (Bolli) 1959, Page
Globorotalia angulata Zone 1960, Olsson
Globorotalia psuedobulloides Zone 1960, Olsson
Globorotalia wilcoxensis (Cushman and Ponton var. acuta Toulmin) 1957 a and b, Loeblich and Tappan; 1959, Page
Globorotalia pseudoscitula (Glaessner) 1957 a and b, Loeblich and Tappan; 1959, Page
Globorotalia convexa (Subbotina) 1957 a and b, Loeblich and Tappan; 1959, Page
Chiloguembelina crinita (Glaessner) 1957 a and b, Loeblich and Tappan; 1959, Page
Heterohelix wiloxensis (Cushman & Ponton) 1957 a and b, Loeblich and Tappan; 1959, Page
Globigerina aquiensis (Loeblich & Tappan) 1957 a and b, Loeblich and Tappan; 1959, Page
Globigerina spiralis Bolli 1957 a and b, Loeblich and Tappan; 1959, Page
Globigerina inaequispira Subbotina 1957 a and b, Loeblich and Tappan; 1959, Page
Globigerina chascanona (Loeblich & Tappan) 1957 a and b, Loeblich and Tappan; 1959, Page
Globigerina triloculinoides 1957 a and b, Loeblich and Tappan; 1959, Page
Planktonic Foraminifera Reference
Globigerina mckannai 1957 a and b, Loeblich and Tappan; 1959, Page
Globorotalia tribulosa (Loeblich & Tappan) 1957 a and b, Loeblich and Tappan; 1959, Page
Globorotalia trichotrocha (Loeblich & Tappan) 1957 a and b, Loeblich and Tappan; 1959, Page
Globorotalia perclara 1957 a and b, Loeblich and Tappan; 1959, Page
21
Globorotalia convexa Subbotina 1957 a and b, Loeblich and Tappan; 1959, Page
Globorotalia hispidicidaris (Loeblich & Tappan) 1957 a and b, Loeblich and Tappan; 1959, Page
Globorotalia angulata 1957 a and b, Loeblich and Tappan; 1959, Page
Globorotalia reissi 1957 a and b, Loeblich and Tappan; 1959, Page
Globorotalia acuta Toulmin 1957 a and b, Loeblich and Tappan; 1959, Page
Globorotalia apanthesma 1957 a and b, Loeblich and Tappan; 1959, Page
Globorotalia occlusa 1957 a and b, Loeblich and Tappan; 1959, Page
Globorotalia psuedoscitula 1957 a and b, Loeblich and Tappan; 1959, Page
Globorotalia psuedomenardii Bolli 1957 a and b, Loeblich and Tappan; 1959, Page
Globorotalia elongate Glaessner 1957 a and b, Loeblich and Tappan; 1959, Page
Globorotalia imitata Subbotina 1957 a and b, Loeblich and Tappan; 1959, Page
Globorotalia aequa 1957 a and b, Loeblich and Tappan; 1959, Page
Globorotalia esnaensis(?) LeRoy 1957 a and b, Loeblich and Tappan; 1959, Page; 1965, Berggren
Calcareous Nannofossils (Single-celled Algae) Fasciculithus tympaniformes zone Piscataway Member, Aquia Formation [NP5, CP4]
1984, Hazel et al
Pollen (Tree and other plants)
Carya <29um Angiosperm – flowering plant (Hickory Family) 1991, Frederickson; 1998, Frederickson
Osculapollis? colporatus Angiosperm (normapolles group) 1991, Frederickson; 1998, Frederickson
Momipites actinus Angiosperm (Walnut Family) 1991, Frederickson; 1998, Frederickson
Choanopollenites conspicuus Angiosperm (normapolles group) 1991, Frederickson; 1998, Frederickson
Plants
Pityostrobus sp. Extinct pinaceous cone 1977, Miller
22
Appendix 4. List of Taxa Identified from the Internet, Collections of Amateur Collectors
Table 1. Itano Family Collection
Source: http://www.itano.net/fossils/marylan2/marylan2.htm.
Dated May 27, 2001. Collected in 1960's by Wayne, David, and Glenn Itano.
Accessed: 12/6/2007; 1/4/2008; 7/25/2008
Location: Clifton Beach, just above Smith Point, MD
Vertebrates
Reptiles
Thecachampsa sp. (crocodile teeth)
Trionyx virginiana Clark (turtle shell)
Fish
Myliobatis copeanus Clark
Otodus obliquus Agassiz
Striatolamia macrota Agassiz
Physogaleus secundus
Chimaeroid fish
Invertebrates
Molluscs
Gastropods
Turritella sp. (internal mold)
Bivalves
Ostrea compressirostra Say
Table 2: Jayson Kowinsky Collection
Source: http://fossilguy.com/sites/potomac/liv_col.htm
Dated August 8, 2005.
Authors: Jayson Kowinsky and Amy
Location: Piscataway Member, Aquia Formation, Potomac River, Charles Co. MD
Genus - Species Common Name/ Material Found
Carcharias hopei Sand tiger shark
Cretolamna sp. (appendiculata?) Mackerel-type shark
Paleohypotodus rutoti Sand tiger/Mackerel-type shark
Striatolamia striata Sand tiger shark
Myliobatis sp. Ray crushing plates
Thecachampsa sp. Crocodile teeth, scutes, femur
Turtle plastron fragment Indet.
Trionyx sp. Freshwater turtle
Turritella sp. Gastropod
23
Table 3. List of Taxa Found in the Late Paleocene Aquia Formation, Piscataway Member
Source: The Life and Times of Long Dead Sharks, http://www.elasmo.com/frameMe.html?file=paleo/fauna/cb_palaeo.html&menu=bin/menu_fauna-alt.html
Authors: Jim Bourdon, Gary Grimsley, Bill Heim, and Rob Weems. Copyrighted 2002-2007.
CHONDRICHTHYAN FAUNA Cartilaginous fish
Ischyodus dolloi Ratfish
SYNECHODONTIFORMES Duffin & Ward 1993
Extinct Neoselachian shark with two dorsal fins with spines and distinct clutching teeth
Paraorthacodus clarkii Eastman, 1901 Extinct synechodontid shark
HEXANCHIFORMES Buen 1926 Six- and Seven-gilled sharks, Cow shark, Primitive shark, Bluntnose shark, Broadnose shark, Big-eyed shark
cf. Hexanchus sp. Extinct six-gilled shark
Notidanodon sp. Extinct cow shark
SQUALIFORMES Goodrich 1909 Bramble shark, Dogfish shark, Rough shark, Lantern shark, Sleeper shark
Squalus cf. minor (Winkler, 1874) Spurdog/ Spiny Dogfish shark
"Megasqualus" orpiensis Winkler, 1874 Extinct dogfish shark
SQUATINIFORMES Buen 1926 Angel shark
Squatina "prima" (Winkler, 1874) Extinct Angel shark
HETERODONTIFORMES Berg 1937 Bullhead shark
Heterodontus cf. lerichei (Casier 1943) Bullhead shark
ORECTOLOBIFORMES Applegate 1972 Nurse shark, Whale shark, Carpet shark, Blind shark, Zebra shark
Ginglymostoma cf. subafricanum Arambourg 1952
Extinct nurse shark
Delpitoscyllium africanum (Leriche 1927) Extinct nurse shark
Palaeorhincodon wardi (Herman, 1975) Extinct whale shark
LAMNIFORMES Berg 1958 Mackeral shark, Thresher shar, Megamouth shark, Ragged-tooth shark, Goblin shark, Basking shark
Anomotodon cf. novus (Winkler 1874) Extinct goblin shark
Odontaspis winkleri (Leriche, 1905) Smalltooth sand tiger
24
Palaeohypotodus rutoti (Agassiz, 1843) Extinct sand tiger shark
Brachycarcharias lerichei (Casier, 1946) Extinct sand tiger shark
Hypotodus verticalis (Agassiz, 1843) Extinct sand tiger shark
Striatolamia striata (Winkler, 1874) Extinct sand tiger- like shark
Striatolamia sp. Extinct sand tiger- like shark
Jaekelotodus robustus (Leriche, 1921) Extinct lamniform shark
Isurolamna inflata (Leriche, 1905) Extinct mackerel shark
Cretalamna appendiculata (Agassiz 1843) Extinct mackerel shark
Otodus obliquus (Agassiz, 1843) Extinct mackerel shark
Palaeocarcharodon orientalis (Sinzow, 1899)
Extinct lamniform
CARCHARINIFORMES Compagno 1973 Requiem shark, Ground shark, Cat shark, Hound shark, Hammerhead shark, Whale shark, Blue shark
Pachygaleus lefevrei (Daimeries, 1891) Extinct hound shark
Galeorhinus sp. Extinct tope shark
Palaeogaleus sp. Extinct hound shark
Triakis sp. Extinct sound shark
? Scyliorhinus sp. Cat shark
Scyliorhinus cf. ptychtus (Noubhani & Cappetta, 1997)
Extinct cat shark
Premontreia cf. subulidens (Arambourg, 1952)
Extinct cat shark
Abdounia beaugei (Arambourg, 1935) Extinct requiem shark
Abdounia sp. Extinct requiem shark
RAJIFORMES Berg 1940 Order, Skates
MYLIOBATIFORMES Compagno 1973 Order, Stingrays
Hypolophodon cf. sylvestris Extinct stingray
Coupatezia woutersi (Winkler, 1874) Extinct stingray
Dasyatis sp. Whiptail Ray
25
cf. "Myliobatis" dixoni (Agassiz, 1843) Eagle ray
"Myliobatis" sp. Eagle ray
Rhinoptera sp. Cow-nose ray
"Myliobatis" sulcidens Extinct ray species
Burnhamia sp. Extinct mobulid ray
Appendix 5. List of Taxa Collected by Mike Folmer and Chuck Bell, Douglas Point SRMA,
Charles County, MD and vicinity
Genus - Species Common Name
Anomotodon cf. novus Extinct goblin shark
Anomotodon novus Extinct goblin shark
Brachycarcharias lerichei Extinct mackeral shark
Cretalamna appendiculata Extinct mackerel shark
Cybium sp. Osteichthyes - Bony fish
Delpitoscyllium africanum Extinct nurse shark
Dollochelys coatesi Sea turtle
Ginglymostoma africanum Extinct nurse shark
Hetereodontus cf. lerichei Bullhead shark
Hypolophodon cf. sylvestris Extinct Stingray
Carcharias hopei now Hypotodus verticalis
Sand tiger shark
Ischyodus dolloi Extinct ratfish
Isurolamna inflata Extinct mackerel shark
Lamna lerichei Mackerel shark
Myliobatis sp. Eagle Ray
Myliobatis sulcidens Eagle Ray
“Myliobatis” sulcidens Extinct ray species
Notidanodon loozi Cow shark
Odontaspis winkleri Extinct mackerel shark
Ostracian sp. Bony (Box) Fish
Otodus obliqus Extinct mackerel shark
Pachygaleus lefevrei Extinct hound shark
Palaeocarcharodon orientallis Extinct mackeral shark
Palaeogaleus lefevrei Extinct Hound shark
Palaeogaleus sp. Extinct Hound shark
Palaeohypotodus rutoti Extinct sand tiger-like shark genus
Parabula marylandica Bony fish
Paraorthacodus clarkii Extinct shark
Phyllodus toliapicus Bony Fish
26
Scyliorhinus gilberti Cat Shark
Scyliorhinus brivesi Cat Shark
Squalus sp. Dogfish shark; also spurdog
Squatina “prima” Extinct angel shark
Striatolamia striata Extinct sand tiger-like shark
Fish premaxillary indet. Indet.
Thoracosaurus neocesariensis Crocodile
Eosuchus lerichei Crocodile
Eosuchus minor Crocodile
Scutes indet. Crocodile
Shell fragments Turtle indet.
Pinaceous cone Pityostrobus sp.
Limb bones indet. Bird? Crocodile?
Crocodile Vertebrae Indet.
Glyptoactis sp. Mollusk
Ostrea compressirosta Oyster
Turitella sp. Sea snail
Mollusk Indet.
27
Figure 6. Poster showing paleontological resources in and around the BLM Douglas Point SRMA. Specimens were
donated to the BLM by Mike Folmer and Chuck Ball.
28
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